There is little love for the SAT. How little, you ask? When a massive cheating scandal erupted this fall, fewer people rushed to defend the test than rose to defend Penn State officials for allegedly covering up the sexual abuse of children. But as unpopular as the iconic SAT may be — among students and many educational activists alike — it’s actually pretty good at what it’s designed to do, which is to serve as a common measure across the hodgepodge of academic standards, grading systems and norms being used by America’s sprawling 25,000 high schools.

Unlike many of the tests that the education world loves to argue about, the SAT is an optional test; students choose to take it if they want to attend schools that require it for admission. So SAT angst is limited to the college-bound. (The test is administered by the New York-based nonprofit College Board, which is also in charge of high school Advanced Placement tests.) And although its only true fans are the intellectually insecure, the SAT, which used to be an acronym for Scholastic Aptitude Test, doesn’t show how smart or savvy students are or how successful, happy, or impactful they’re likely to be in life. But on average, it does fairly accurate gauge on how well students will do in their first year of college. That’s something admissions officials want to know. And that’s why good scores can boost an applicant’s chances of getting in and low scores can torpedo them.

The SAT was front-page news this fall when 20 students were arrested in a New York suburb for cheating on it. The scandal was sensational but straightforward: high-scoring students used fake IDs to take the test for other students. One enterprising young man allegedly offered his customers a pay-by-installment plan and also factored their financial situations into his rates. Some locals indicated that the cheating was an open secret in these communities.

Although the brazenness on display in Long Island’s Nassau County may be somewhat unusual, cheating on the SAT is not. The head of test security for the College Board recently told the New York Times that during the 2010-11 academic year, the nonprofit conducted “about 9,600 investigations of SAT testing irregularities, including fire alarms going off during testing and reports of test taker impersonation.” That averages out to be slightly more than one investigation per SAT test center that year. And surely no one thinks the ACT — the SAT counterpart that is used more widely for colleges in the Midwest and West — is immune from cheating either. In fact, prosecutors say ACT cheating may have occurred on Long Island as well.

Most people in education are willing to tolerate these problems — and the tyranny of the SAT — because it’s a useful tool. Originally intended to help eliminate bias against various socioeconomic groups, today the SAT functions largely to address grading bias. It’s a barometer to help admissions officials make sense of the country’s diverse educational landscape, from the highly regarded and perhaps grade-grubbing private schools to the rigorous and not so rigorous public schools.

Taken over an almost four-hour period, the SAT today is a three-part test on a 2400-point scale. (So take note if you’re over 30: bragging about your 1400 or 1500 doesn’t sound so impressive now that the 1600-point scale is considered ancient history.) Many affluent kids use various SAT preparation programs — a legal way to bump your scores — and others will try whatever they think they can get away with to gain an edge.

The pressure on students, along with concerns that the test is unfair for some racial and ethnic groups, are reasons many advocates and even some colleges want to do away with the SAT. The anti-standardized testing organization FairTest maintains a list of SAT-optional schools. At first glance, it seems impressive that about 850 colleges signed up. But many of the schools are not selective. Many are small religious schools or vocational or for-profit ones. Others are still using the SAT test in some way, just not as a formulaic criterion for admissions. Some admissions experts say that the whole SAT-optional movement is more of a marketing scam by colleges than a serious effort to evaluate applicants differently.

More than anything else, the cheating shows how marginal the efforts to marginalize the SAT are. Students cheat because the test matters. A lot. Smaller schools like Bates College in Maine can ditch the test and still work through manageable numbers of applicants. About 5,100 students applied to Bates last year, not an easy workload for admissions officials but not insane. More than 28,000 applied to the University of Illinois, which, like other big schools, needs a tool like the SAT. And if you look at the college landscape in this country, many more students apply to and attend schools like Illinois than ones like Bates.

One possible threat to the SAT’s dominance is the Common Core State Standards Initiative. Armed with federal dollars, two groups of states are working to develop new assessments that are designed to show whether kids are learning the new Common Core standards, which 45 states and the District of Columbia have agreed to adopt. These tests are supposed to measure high school achievement and post-secondary readiness and, if successfully implemented on a widespread basis — and that’s a big if — could one day supplant the SAT.

But in the meantime, the best we can do is try to stop the cheating on the SAT because in the land of the blind, the one-bubble test is king. The College Board has retained former FBI director Louis Freeh to evaluate its test security. Penn State is also using Freeh, who may be on his way to developing a lucrative post-FBI career cleaning up educational messes. He certainly has his work cut out for him.

Rotherham is a co-founder and partner at the nonprofit Bellwether Education, a national non-profit organization which, among other activities, does paid consulting work for clients including school districts, charter schools, and educational organizations around the country. The views expressed are solely his own.